Compact sparse array antennas, operating in a wide frequency band, for radar sensing systems based on specific antenna radiating elements formed in a multilayer substrate and having considerably reduced dimensions due to application of an artificial medium (metamaterial) of a high relative permittivity.
As a way to improve the electrical performance of a radar system, a high-gain antenna can be used. Especially, such problem is crucial in remote sensing of an undersurface or hidden object due to its small signal reflectivity. Also, to provide radar imaging of such object, an antenna has to be operating in a wide frequency band. However, a typical wideband antenna (such as phase or sparse array antenna) used in a radar system has large dimensions, especially, at a low-gigahertz frequency range, that considerably limits areas of its applications.
Thus, it is important to develop such antenna systems which will be compact and, as a result, can be used in a lightweight radar system having wide application areas.